Pasternak, Jeffrey J.

Background and Purpose— There is currently controversy on the ideal anesthesia strategy during mechanical thrombectomy for acute ischemic stroke. We performed a systematic review and meta-analysis of studies comparing clinical and angiographic outcomes of patients undergoing general anesthesia (GA group) and those receiving either local anesthesia or conscious sedation (non-GA group). Methods— A literature search on anesthesia and endovascular treatment of acute ischemic stroke was performed. Using random-effects meta-analysis, we evaluated the following outcomes: recanalization rate, good functional outcome at 90 days (modified Rankin Score≤2), symptomatic intracranial hemorrhage, death, vascular complications, respiratory complications, procedure time, and time to groin puncture. Results— Twenty-two studies (3 randomized controlled trials and 19 observational studies), including 4716 patients (1819 GA and 2897 non-GA) were included. In the nonadjusted analysis, patients in the GA group had higher odds of death (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.66–2.45) and respiratory complications (OR, 1.70; 95% CI, 1.22–2.37) and lower odds of good functional outcome (OR, 0.58; 95% CI, 0.48–0.64) compared with the non-GA group. There was no difference in procedure time between the 2 primary comparison groups. When adjusting for baseline National Institutes of Health Stroke Scale, GA was still associated with lower odds of good functional outcome (OR, 0.59; 95% CI, 0.29–0.94). When considering studies performed in the stent-retriever/aspiration era, there was no significant difference in good neurological outcome rates (OR, 0.84; 95% CI, 0.67–1.06). Conclusions— Acute ischemic stroke patients undergoing intra-arterial therapy may have worse outcomes when treated with GA as compared with conscious sedation/local anesthesia. However, major limitations of current evidence (ie, retrospective studies and selection bias) indicate a need for adequately powered, multicenter randomized controlled trials to answer this question.

OBJECTIVE Historically, performing neurosurgery with the patient in the sitting position offered advantages such as improved visualization and gravity-assisted retraction. However, this position fell out of favor at many centers due to the perceived risk of venous air embolism (VAE) and other position-related complications. Some neurosurgical centers continue to perform sitting-position cases in select patients, often using modern monitoring techniques that may improve procedural safety. Therefore, this paper reports the risks associated with neurosurgical procedures performed in the sitting position in a modern series. METHODS The authors reviewed the anesthesia records for instances of clinically significant VAE and other complications for all neurosurgical procedures performed in the sitting position between January 1, 2000, and October 8, 2013. In addition, a prospectively maintained morbidity and mortality log of these procedures was reviewed for instances of subdural or intracerebral hemorrhage, tension pneumocephalus, and quadriplegia. Both overall and specific complication rates were calculated in relation to the specific type of procedure. RESULTS In a series of 1792 procedures, the overall complication rate related to the sitting position was 1.45%, which included clinically significant VAE, tension pneumocephalus, and subdural hemorrhage. The rate of any detected VAE was 4.7%, but the rate of VAE requiring clinical intervention was 1.06%. The risk of clinically significant VAE was highest in patients undergoing suboccipital craniotomy/craniectomy with a rate of 2.7% and an odds ratio (OR) of 2.8 relative to deep brain stimulator cases (95% confidence interval [CI] 1.2–70, p = 0.04). Sitting cervical spine cases had a comparatively lower complication rate of 0.7% and an OR of 0.28 as compared with all cranial procedures (95% CI 0.12–0.67, p < 0.01). Sitting cervical cases were further subdivided into extradural and intradural procedures. The rate of complications in intradural cases was significantly higher (OR 7.3, 95% CI 1.4–39, p = 0.02) than for extradural cases. The risk of VAE in intradural spine procedures did not differ significantly from sitting suboccipital craniotomy/craniectomy cases (OR 0.69, 95% CI 0.09–5.4, p = 0.7). Two cases (0.1%) had to be aborted intraoperatively due to complications. There were no instances of intraoperative deaths, although there was a single death within 30 days of surgery. CONCLUSIONS In this large, modern series of cases performed in the sitting position, the complication rate was low. Suboccipital craniotomy/craniectomy was associated with the highest risk of complications. When appropriately used with modern anesthesia techniques, the sitting position provides a safe means of surgical access.

Background: Thyroid-stimulating hormone (TSH)–secreting pituitary adenomas are a rare cause of secondary hyperthyroidism. Anesthetic management of these patients has not been formally described in the literature. Materials and Methods: Patients who underwent resection of a TSH-secreting pituitary adenoma during 1987 to 2012 at a single institution were identified. Preoperative thyroid hormone state, anesthetic management, and outcome were recorded. Hemodynamic associations with intraoperative events were compared between those who were hyperthyroid and euthyroid at the time of surgery. Results: Of 2268 patients having transsphenoidal resection of a pituitary tumor, 19 (0.84%) had resection of a TSH-secreting adenoma. At the time of surgery, 6 (32%) were hyperthyroid, 11 (58%) were euthyroid, and 2 (10%) were hypothyroid based on serum thyroxine concentration. General anesthesia was maintained with a potent inhaled anesthetic in all patients, and included nitrous oxide in 18 of 19 (95%). Seventeen (90%) had an arterial catheter placed for surgery. Only 1 patient (5%) required an intraoperative blood transfusion. There were no significant differences in heart rate or blood pressure at induction of anesthesia, upon intranasal injection of local anesthetic containing epinephrine, or upon emergence from anesthesia, between patients who were chemically hyperthyroid or euthyroid. Twelve of 19 (63%) had tumor extension beyond the sella turcica. Common complications were nausea and vomiting (42%), diabetes insipidus (32%), and temporary or permanent hypopituitarism (42%). Conclusions: Patients having resection of TSH-secreting pituitary adenomas can present in any thyroid state. An awareness of risks and potential complications in patients with TSH-secreting adenomas can help tailor perioperative care.

Background and purpose Many studies have suggested a relationship between the type of anesthesia provided during intra-arterial therapy for acute ischemic stroke and patient outcomes. Variability in blood pressure and hypotension have previously been identified as possible reasons for worse outcomes in acute stroke. Our aim was to investigate hemodynamic parameters and neurological outcomes of patients receiving either general anesthesia or conscious sedation for intra-arterial therapy of acute stroke. Methods We performed a retrospective review of patients undergoing intra-arterial therapy from December 2008 to March 2015. Demographic data, baseline National Institutes of Health Stroke Scale score, preoperative physiological variables, procedural details, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate, and modified Rankin Scale scores were recorded. Results 99 patients were included in the study, with 38 receiving general anesthesia and 61 receiving conscious sedation. Patients who received general anesthesia had a lower maximum SBP (p=0.02), minimum SBP (p<0.0001), minimum DBP (p<0.0001), and minimum MAP (p<0.0001). On multivariate analysis, general anesthesia was associated with lower minimum SBP (p=0.04), DBP (p=0.02), and MAP (p=0.007). Conscious sedation was associated with more favorable neurological outcomes (p=0.02). Patients with favorable neurological outcomes had a lower maximum variability in SBP (p=0.01) and MAP (p=0.03), as well as a higher minimum DBP (p=0.03). Conclusions Patients with acute ischemic stroke undergoing intra-arterial therapy with general anesthesia had lower minimum SBP, DBP, and MAP, greater fluctuations in blood pressure, and less favorable outcomes. More studies are needed to examine the implications of variable and reduced blood pressures and neurological outcomes.

BackgroundPast research has explored patients' expectations about the informed consent process. However, it is currently unknown if the complexity of the surgical procedure influences the type of anesthesia‐related risks that patients wish disclosed. This study explored fears of anesthesia‐related complications and whether these changed based on severity of surgery classification.MethodsPatients presenting to our pre‐operative evaluation clinic from February 2013 to May 2013 were asked to participate in a survey‐based study meant to evaluate their perception of five possible anesthetic risks (peripheral nerve injury, death, nausea and vomiting, heart attack and stroke) when confronted with differing levels of surgical severity.ResultsOne thousand surveys were administered, and 894 were returned for an overall response rate of 89%. Fear of death was the greatest concern as compared to the other risk factors independent of the severity of surgery. The level of fear for all risk factors, with the exception of stroke and heart attack, were dependent on the severity of surgery. Fear of death decreased as the severity of surgery decreased (major 46%, moderate 38%, minor 25%). For major surgery, the fear of perioperative death differed significantly with age (P < 0.001); specifically, with increasing age came a lessened fear of death.ConclusionAwareness by anesthesia providers of those fears that patients report may allow for a more personalized approach to providing information that may better allay anxiety. Further, these results may better tailor the informed consent process to one that meets particular patient concerns.

BackgroundPrinciples of informed consent are ethically, morally, and legally grounded in physicians' responsibility to patients. This study examined patient expectations regarding the informed consent during the perioperative process, specifically risk information exchange, preferred method and timing of delivery, and the roles that patient anxiety and understanding might play.MethodsFive hundred patients seen in our pre‐operative clinic were surveyed by written questionnaire. Patients were asked about their level of agreement with a number of statements pertaining to informed consent and their preferences for discussion of types of risks. Anxiety concerns, impact of ability to understand complexities of care, preferences for timing, and method of presentation were assessed.ResultsFour hundred eleven of 500 surveys (82%) were completed. A majority of respondents (92% and 80%, respectively) believed the risk of common but less consequential complications and rare yet severe complications should be discussed. Only 21% agreed that anxiety generated by discussion of risks outweighed benefit and only 6% agreed that discussion of risks should be restricted based on patient inability to appreciate complexities of care. Discussion was preferred on the day of surgery, 1 week before, and 1 month before in 46%, 35%, and 16% of respondents, respectively, and independent of level of anxiety generated by such discussion (P = 0.87). Respondents preferred discussion with their anaesthesia provider alone (44%) or in combination with written information (52%) as compared with written information only (4%) (P < 0.01).ConclusionsGreater awareness of patient preferences and expectations may result in better information exchange between anaesthesia providers and their patients.

Background Laboratory studies suggest that nitrous oxide augments brain injury after ischemia or hypoxia. The authors examined the relation between nitrous oxide use and outcomes using data from the Intraoperative Hypothermia for Aneurysm Surgery Trial. Methods The Intraoperative Hypothermia for Aneurysm Surgery Trial was a prospective randomized study of the impact of intraoperative hypothermia (temperature = 33 degrees C) versus normothermia (temperature = 36.5 degrees C) in patients with aneurysmal subarachnoid hemorrhage undergoing surgical clipping. Anesthesia was dictated by a limited-options protocol with the use of nitrous oxide determined by individual anesthesiologists. All patients were assessed daily for 14 days after surgery or until hospital discharge. Neurologic and neuropsychological testing were conducted at 3 months after surgery. Outcome data were analyzed via both univariate tests and multivariate logistic regression analysis correcting for factors thought to influence outcome. An odds ratio (OR) greater than 1.0 denotes a worse outcome in patients receiving nitrous oxide. Results Outcome data were available for 1,000 patients, of which 373 received nitrous oxide. There was no difference between groups in the development of delayed ischemic neurologic deficit. At 3 months after surgery, there were no significant differences between groups in any outcome variable: Glasgow Outcome Score (OR, 0.84; 95% confidence interval [CI], 0.63-1.14; P = 0.268), National Institutes of Health Stroke Scale (OR, 1.29; 95% CI, 0.96-1.73; P = 0.087), Rankin Disability Score (OR, 0.84; 95% CI, 0.61-1.15; P = 0.284), Barthel Activities of Daily Living Index (OR, 1.01; 95% CI, 0.68-1.51; P = 0.961), or neuropsychological testing (OR, 1.26; 95% CI, 0.85-1.87; P = 0.252). Conclusions In a population of patients at risk for ischemic brain injury, nitrous oxide use had no overall beneficial or detrimental impact on neurologic or neuropsychological outcomes.

Background The authors explored the relationship between nitrous oxide use and neurologic and neuropsychological outcome in a population of patients likely to experience intraoperative cerebral ischemia: those who had temporary cerebral arterial occlusion during aneurysm clipping surgery. Methods A post hoc analysis of a subset of the data from the Intraoperative Hypothermia for Aneurysm Surgery Trial was conducted. Only subjects who had temporary arterial occlusion during surgery were included in the analysis. Metrics of short-term and long-term (i.e., 3 months after surgery) outcome were evaluated via both univariate and multivariate logistic regression analysis. An odds ratio (OR) greater than 1.0 denotes a worse outcome in patients receiving nitrous oxide. Results The authors evaluated 441 patients, of which 199 received nitrous oxide. Patients receiving nitrous oxide had a greater risk of delayed ischemic neurologic deficits (i.e., the clinical manifestation of vasospasm) (OR, 1.78, 95% confidence interval [CI], 1.08-2.95; P = 0.025). However, at 3 months after surgery, there was no difference in any metric of gross neurologic outcome: Glasgow Outcome Score (OR, 0.67; CI, 0.44-1.03; P = 0.065), Rankin Score (OR, 0.74; CI, 0.47-1.16; P = 0.192), National Institutes of Health Stroke Scale (OR, 1.02; CI, 0.66-1.56; P = 0.937), or Barthel Index (OR, 0.69; CI, 0.38-1.25; P = 0.22). The risk of impairment on at least one test of neuropsychological function was reduced in those who received nitrous oxide (OR, 0.56; CI, 0.36-0.89; P = 0.013). Conclusion In this patient population, use of nitrous oxide was associated with an increased risk for the development of delayed ischemic neurologic deficits; however, there was no evidence of detriment to long-term gross neurologic or neuropsychological outcome.